ISSN:
0021-8995
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
For some time, polyimides have enjoyed a significant degree of superiority over the other classes of thermo-oxidatively stable polymers. This superiority is, however, offset by the tremendous difficulty associated with the processing of polyimides. In an effort to understand these difficulties and their causes, several experiments were performed which reflect the roles that reaction temperature and hydrolysis (caused by the presence of water) play during amidization and imidization. Temperatures between 0° and 120°C were found to result in progressively lower-viscosity polyamic acids whose equivalent weights varied only slightly with increasing reaction temperatures. The presence of hydroxide ions from water were shown to cause degradation of the polymer, and the combination of temperatures above 120°C and hydroxide ions results in the rapid degradation of the polymer and lower molecular weight polyimides.
Zusätzliches Material:
8 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/app.1971.070151118
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